#!/bin/sh

set -e

# http://erlang.org/doc/man/run_erl.html
# If defined, disables input and output flow control for the pty
# opend by run_erl. Useful if you want to remove any risk of accidentally
# blocking the flow control by using Ctrl-S (instead of Ctrl-D to detach),
# which can result in blocking of the entire Beam process, and in the case
# of running heart as supervisor even the heart process becomes blocked
# when writing log message to terminal, leaving the heart process unable
# to do its work.
RUN_ERL_DISABLE_FLOWCNTRL=${RUN_ERL_DISABLE_FLOWCNTRL:-true}
export $RUN_ERL_DISABLE_FLOWCNTRL

if [ "$TERM" = "dumb" -o -z "$TERM" ]; then
  export TERM=screen
fi

# OSX does not support readlink '-f' flag, work
# around that
case $OSTYPE in 
    darwin*)
        SCRIPT=$(readlink $0 || true)
    ;;
    *)
        SCRIPT=$(readlink -f $0 || true)
    ;;
esac
[ -z $SCRIPT ] && SCRIPT=$0
SCRIPT_DIR="$(cd `dirname "$SCRIPT"` && pwd -P)"
RELEASE_ROOT_DIR="$(cd "$SCRIPT_DIR/.." && pwd -P)"
# Make the value available to variable substitution calls below
export REL_NAME="{{ rel_name }}"
REL_VSN="{{ rel_vsn }}"
ERTS_VSN="{{ erts_vsn }}"
CODE_LOADING_MODE="${CODE_LOADING_MODE:-embedded}"
REL_DIR="$RELEASE_ROOT_DIR/releases/$REL_VSN"
ERL_OPTS="{{ erl_opts }}"
RUNNER_LOG_DIR="${RUNNER_LOG_DIR:-$RELEASE_ROOT_DIR/log}"

# start/stop/install/upgrade pre/post hooks
PRE_START_HOOKS="{{{ pre_start_hooks }}}"
POST_START_HOOKS="{{{ post_start_hooks }}}"
PRE_STOP_HOOKS="{{{ pre_stop_hooks }}}"
POST_STOP_HOOKS="{{{ post_stop_hooks }}}"
PRE_INSTALL_UPGRADE_HOOKS="{{{ pre_install_upgrade_hooks }}}"
POST_INSTALL_UPGRADE_HOOKS="{{{ post_install_upgrade_hooks }}}"
STATUS_HOOK="{{{ status_hook }}}"

relx_usage() {
    command="$1"

    case "$command" in
        unpack)
            echo "Usage: $REL_NAME unpack [VERSION]"
            echo "Unpacks a release package VERSION, it assumes that this"
            echo "release package tarball has already been deployed at one"
            echo "of the following locations:"
            echo "      releases/<relname>-<version>.tar.gz"
            echo "      releases/<version>/<relname>-<version>.tar.gz"
            echo "      releases/<version>/<relname>.tar.gz"
            ;;
        install)
            echo "Usage: $REL_NAME install [VERSION]"
            echo "Installs a release package VERSION, it assumes that this"
            echo "release package tarball has already been deployed at one"
            echo "of the following locations:"
            echo "      releases/<relname>-<version>.tar.gz"
            echo "      releases/<version>/<relname>-<version>.tar.gz"
            echo "      releases/<version>/<relname>.tar.gz"
            echo ""
            echo "     --no-permanent   Install release package VERSION but"
            echo "                      don't make it permanent"
            ;;
        uninstall)
            echo "Usage: $REL_NAME uninstall [VERSION]"
            echo "Uninstalls a release VERSION, it will only accept"
            echo "versions that are not currently in use"
            ;;
        upgrade)
            echo "Usage: $REL_NAME upgrade [VERSION]"
            echo "Upgrades the currently running release to VERSION, it assumes"
            echo "that a release package tarball has already been deployed at one"
            echo "of the following locations:"
            echo "      releases/<relname>-<version>.tar.gz"
            echo "      releases/<version>/<relname>-<version>.tar.gz"
            echo "      releases/<version>/<relname>.tar.gz"
            echo ""
            echo "     --no-permanent   Install release package VERSION but"
            echo "                      don't make it permanent"
            ;;
        downgrade)
            echo "Usage: $REL_NAME downgrade [VERSION]"
            echo "Downgrades the currently running release to VERSION, it assumes"
            echo "that a release package tarball has already been deployed at one"
            echo "of the following locations:"
            echo "      releases/<relname>-<version>.tar.gz"
            echo "      releases/<version>/<relname>-<version>.tar.gz"
            echo "      releases/<version>/<relname>.tar.gz"
            echo ""
            echo "     --no-permanent   Install release package VERSION but"
            echo "                      don't make it permanent"
            ;;
        status)
            echo "Usage: $REL_NAME status"
            echo "Obtains node status information."
            ;;
        *)
            echo "Usage: $REL_NAME {start|start_boot <file>|foreground|stop|restart|reboot|pid|ping|console|console_clean|console_boot <file>|attach|remote_console|upgrade|downgrade|install|uninstall|versions|escript|rpc|rpcterms|eval|status}"
            ;;
    esac
}

find_erts_dir() {
    __erts_dir="$RELEASE_ROOT_DIR/erts-$ERTS_VSN"
    if [ -d "$__erts_dir" ]; then
        ERTS_DIR="$__erts_dir";
        ROOTDIR="$RELEASE_ROOT_DIR"
    else
        __erl="$(which erl)"
        code="io:format(\"~s\", [code:root_dir()]), halt()."
        __erl_root="$("$__erl" -boot no_dot_erlang -noshell -eval "$code")"
        ERTS_DIR="$__erl_root/erts-$ERTS_VSN"
        ROOTDIR="$__erl_root"
    fi
}

# Get node pid
relx_get_pid() {
    if output="$(relx_nodetool rpcterms os getpid)"
    then
        echo "$output" | sed -e 's/"//g'
        return 0
    else
        echo "$output"
        return 1
    fi
}

relx_get_nodename() {
    id="longname$(relx_gen_id)-${NAME}"
    "$BINDIR/erl" -boot start_clean \
        -eval '[H]=tl(string:tokens(atom_to_list(node()),"@")), io:format("~s~n",[H]), halt()' \
        -noshell ${NAME_TYPE} $id
}

# Connect to a remote node
relx_rem_sh() {
    # Generate a unique id used to allow multiple remsh to the same node
    # transparently
    id="remsh$(relx_gen_id)-${NAME}"

    # Get the node's ticktime so that we use the same thing.
    TICKTIME="$(relx_nodetool rpcterms net_kernel get_net_ticktime)"

    # Setup remote shell command to control node
    exec "$BINDIR/erl" "$NAME_TYPE" "$id" -remsh "$NAME" -boot start_clean \
         -boot_var ERTS_LIB_DIR "$ERTS_LIB_DIR" \
         -setcookie "$COOKIE" -hidden -kernel net_ticktime $TICKTIME
}

# Generate a random id
relx_gen_id() {
    od -t x -N 4 /dev/urandom | head -n1 | awk '{print $2}'
}

# Control a node
relx_nodetool() {
    command="$1"; shift

    "$ERTS_DIR/bin/escript" "$ROOTDIR/bin/nodetool" "$NAME_TYPE" "$NAME" \
                                -setcookie "$COOKIE" "$command" $@
}

# Run an escript in the node's environment
relx_escript() {
    shift; scriptpath="$1"; shift
    export RELEASE_ROOT_DIR

    "$ERTS_DIR/bin/escript" "$ROOTDIR/$scriptpath" $@
}

# Output a start command for the last argument of run_erl
relx_start_command() {
    printf "exec \"%s\" \"%s\"" "$RELEASE_ROOT_DIR/bin/$REL_NAME" \
           "$START_OPTION"
}

relx_get_code_paths() {
    code="{ok, [{release,_,_,Apps}]} = file:consult(\"$REL_DIR/$REL_NAME.rel\"),"\
"lists:foreach(fun(A) ->"\
"   io:fwrite(\"$ROOTDIR/lib/~p-~s/ebin \", [element(1, A), element(2, A)]) "\
"end, Apps),"\
"halt()."

    "$BINDIR/erl" -noshell -boot start_clean -eval "$code"
}

make_out_file_path() {
    # Use output directory provided in the RELX_OUT_FILE_PATH environment variable
    # (default to the current location of vm.args and sys.config)
    DIR=$(dirname $1)
    [ -d "${RELX_OUT_FILE_PATH}" ] && DIR="${RELX_OUT_FILE_PATH}"
    FILE=$(basename $1)
    IN="${DIR}/${FILE}"

    PFX=$(echo $IN   | awk '{sub(/\.[^.]+$/, "", $0)}1')
    SFX=$(echo $FILE | awk -F . '{if (NF>1) print $NF}')
    if [ $RELX_MULTI_NODE ]; then
        echo "${PFX}.${NAME}.${SFX}"
    else
        echo "${PFX}.${SFX}"
    fi
}

# Replace environment variables
replace_os_vars() {
    awk '{
        while(match($0,"[$]{[^}]*}")) {
            var=substr($0,RSTART+2,RLENGTH -3)
            gsub("[$]{"var"}",ENVIRON[var])
        }
    }1' < "$1" > "$2"
}

add_path() {
    # Use $CWD/$1 if exists, otherwise releases/VSN/$1
    IN_FILE_PATH=$2
    if [ -z "$IN_FILE_PATH" ]; then
        if [ -f "$RELEASE_ROOT_DIR/$1" ]; then
            IN_FILE_PATH="$RELEASE_ROOT_DIR/$1"
        else
            IN_FILE_PATH="$REL_DIR/$1"
        fi
    fi
    echo $IN_FILE_PATH
}

check_replace_os_vars() {
    IN_FILE_PATH=$(add_path $1 $2)
    OUT_FILE_PATH="$IN_FILE_PATH"
    ORIG_FILE_PATH="$IN_FILE_PATH.orig"
    if [ $RELX_REPLACE_OS_VARS ]; then
        # Create a new file in the same location as original
        OUT_FILE_PATH=$(make_out_file_path $IN_FILE_PATH)
        # If vm.args.orig or sys.config.orig is present then use that
        if [ -f "$ORIG_FILE_PATH" ]; then
           IN_FILE_PATH="$ORIG_FILE_PATH"
        fi

        # apply the environment variable substitution to $IN_FILE_PATH
        # the result is saved to $OUT_FILE_PATH
        # if they are both the same, then ensure that we don't clobber
        # the file by saving a backup with the .orig extension
        if [ "$IN_FILE_PATH" = "$OUT_FILE_PATH" ]; then
            cp "$IN_FILE_PATH" "$ORIG_FILE_PATH"
            replace_os_vars "$ORIG_FILE_PATH" "$OUT_FILE_PATH"
        else
            replace_os_vars "$IN_FILE_PATH" "$OUT_FILE_PATH"
        fi
    else
        # If vm.arg.orig or sys.config.orig is present then use that
        if [ -f "$ORIG_FILE_PATH" ]; then
           cp "$ORIG_FILE_PATH" "$OUT_FILE_PATH"
        fi
    fi
    echo $OUT_FILE_PATH
}

relx_run_hooks() {
    HOOKS=$1
    for hook in $HOOKS
    do
        # the scripts arguments at this point are separated
        # from each other by | , we now replace these
        # by empty spaces and give them to the `set`
        # command in order to be able to extract them
        # separately
        set `echo "$hook" | sed -e 's/|/ /g'`
        HOOK_SCRIPT=$1; shift
        # all hook locations are expected to be
        # relative to the start script location
        [ "$SCRIPT_DIR/$HOOK_SCRIPT" ] && . "$SCRIPT_DIR/$HOOK_SCRIPT" $@
    done
}

find_erts_dir
export ROOTDIR="$RELEASE_ROOT_DIR"
export BINDIR="$ERTS_DIR/bin"
export EMU="beam"
export PROGNAME="erl"
export LD_LIBRARY_PATH="$ERTS_DIR/lib:$LD_LIBRARY_PATH"
ERTS_LIB_DIR="$(dirname "$ERTS_DIR")/lib"

VMARGS_PATH=$(add_path vm.args $VMARGS_PATH)
# Extract the target node name from node.args
NAME_ARG=$(egrep '^-s?name' "$VMARGS_PATH" || true)
# Perform replacement of variables in ${NAME_ARG}
NAME_ARG=$(eval echo "${NAME_ARG}")

if [ -z "$NAME_ARG" ]; then
    echo "vm.args needs to have either -name or -sname parameter."
    exit 1
fi

# Extract the name type and name from the NAME_ARG for REMSH
NAME_TYPE="$(echo "$NAME_ARG" | awk '{print $1}')"
NAME="$(echo "$NAME_ARG" | awk '{print $2}')"

# User can specify an sname without @hostname
# This will fail when creating remote shell
# So here we check for @ and add @hostname if missing
case "${NAME}" in
    *@*) ;;                             # Nothing to do
    *)   NAME=${NAME}@$(relx_get_nodename);;  # Add @hostname
esac

# Export the variable so that it's available in the 'eval' calls
export NAME

VMARGS_PATH=$(check_replace_os_vars vm.args $VMARGS_PATH)
RELX_CONFIG_PATH=$(check_replace_os_vars sys.config $RELX_CONFIG_PATH)

# Make sure log directory exists
mkdir -p "$RUNNER_LOG_DIR"

PIPE_DIR="${PIPE_DIR:-/tmp/erl_pipes/$NAME/}"

# Extract the target cookie
COOKIE_ARG="$(grep '^-setcookie' "$VMARGS_PATH" || true)"
DEFAULT_COOKIE_FILE="$HOME/.erlang.cookie"
if [ -z "$COOKIE_ARG" ]; then
    if [ -f "$DEFAULT_COOKIE_FILE" ]; then
        COOKIE="$(cat $DEFAULT_COOKIE_FILE)"
    else
        echo "vm.args needs to have a -setcookie, or $DEFAULT_COOKIE_FILE (its permission must be 400) is required."
        exit 1
    fi
else
    # Extract cookie name from COOKIE_ARG
    COOKIE="$(echo "$COOKIE_ARG" | awk '{print $2}')"
fi

cd "$ROOTDIR"

# Check the first argument for instructions
case "$1" in
    start|start_boot)

        # Make sure there is not already a node running
        #RES=`$NODETOOL ping`
        #if [ "$RES" = "pong" ]; then
        #    echo "Node is already running!"
        #    exit 1
        #fi
        # Save this for later.
        CMD=$1
        case "$1" in
            start)
                shift
                START_OPTION="console"
                HEART_OPTION="start"
                ;;
            start_boot)
                shift
                START_OPTION="console_boot"
                HEART_OPTION="start_boot"
                ;;
        esac
        RUN_PARAM="$@"

        # Set arguments for the heart command
        set -- "$SCRIPT_DIR/$REL_NAME" "$HEART_OPTION"
        [ "$RUN_PARAM" ] && set -- "$@" "$RUN_PARAM"

        # Export the HEART_COMMAND
        HEART_COMMAND="$RELEASE_ROOT_DIR/bin/$REL_NAME $CMD"
        export HEART_COMMAND

        mkdir -p "$PIPE_DIR"

        relx_run_hooks "$PRE_START_HOOKS"
        "$BINDIR/run_erl" -daemon "$PIPE_DIR" "$RUNNER_LOG_DIR" \
                          "$(relx_start_command)"
        relx_run_hooks "$POST_START_HOOKS"
        ;;

    stop)
        relx_run_hooks "$PRE_STOP_HOOKS"
        # Wait for the node to completely stop...
        PID="$(relx_get_pid)"
        if ! relx_nodetool "stop"; then
            exit 1
        fi
        while $(kill -s 0 "$PID" 2>/dev/null);
        do
            sleep 1
        done
        relx_run_hooks "$POST_STOP_HOOKS"
        ;;

    restart)
        ## Restart the VM without exiting the process
        if ! relx_nodetool "restart"; then
            exit 1
        fi
        ;;

    reboot)
        ## Restart the VM completely (uses heart to restart it)
        if ! relx_nodetool "reboot"; then
            exit 1
        fi
        ;;

    pid)
        ## Get the VM's pid
        if ! relx_get_pid; then
            exit 1
        fi
        ;;

    ping)
        ## See if the VM is alive
        if ! relx_nodetool "ping"; then
            exit 1
        fi
        ;;

    escript)
        ## Run an escript under the node's environment
        if ! relx_escript $@; then
            exit 1
        fi
        ;;

    attach)
        # Make sure a node IS running
        if ! relx_nodetool "ping" > /dev/null; then
            echo "Node is not running!"
            exit 1
        fi

        shift
        exec "$BINDIR/to_erl" "$PIPE_DIR"
        ;;

    remote_console)
        # Make sure a node IS running
        if ! relx_nodetool "ping" > /dev/null; then
            echo "Node is not running!"
            exit 1
        fi

        shift
        relx_rem_sh
        ;;

    upgrade|downgrade|install|unpack|uninstall)
        if [ -z "$2" ]; then
            echo "Missing version argument"
            echo "Usage: $REL_NAME $1 {version}"
            exit 1
        fi

        COMMAND="$1"; shift

        # Make sure a node IS running
        if ! relx_nodetool "ping" > /dev/null; then
            echo "Node is not running!"
            exit 1
        fi

        relx_run_hooks "$PRE_INSTALL_UPGRADE_HOOKS"

        exec "$BINDIR/escript" "$ROOTDIR/bin/install_upgrade.escript" \
             "$COMMAND" "{'$REL_NAME', \"$NAME_TYPE\", '$NAME', '$COOKIE'}" "$@"

        relx_run_hooks "$POST_INSTALL_UPGRADE_HOOKS"
        ;;

    versions)
        # Make sure a node IS running
        if ! relx_nodetool "ping" > /dev/null; then
            echo "Node is not running!"
            exit 1
        fi

        COMMAND="$1"; shift

        exec "$BINDIR/escript" "$ROOTDIR/bin/install_upgrade.escript" \
             "versions" "{'$REL_NAME', \"$NAME_TYPE\", '$NAME', '$COOKIE'}" "$@"
        ;;

    console|console_clean|console_boot|foreground)
        __code_paths=""
        FOREGROUNDOPTIONS=""
        # .boot file typically just $REL_NAME (ie, the app name)
        # however, for debugging, sometimes start_clean.boot is useful.
        # For e.g. 'setup', one may even want to name another boot script.
        case "$1" in
            console)
                if [ -f "$REL_DIR/$REL_NAME.boot" ]; then
                  BOOTFILE="$REL_DIR/$REL_NAME"
                else
                  BOOTFILE="$REL_DIR/start"
                fi
                ;;
            foreground)
                # start up the release in the foreground for use by runit
                # or other supervision services
                if [ -f "$REL_DIR/$REL_NAME.boot" ]; then
                  BOOTFILE="$REL_DIR/$REL_NAME"
                else
                  BOOTFILE="$REL_DIR/start"
                fi
                FOREGROUNDOPTIONS="-noshell -noinput +Bd"
                ;;
            console_clean)
                __code_paths=$(relx_get_code_paths)
                BOOTFILE="$ROOTDIR/bin/start_clean"
                ;;
            console_boot)
                shift
                BOOTFILE="$1"
                shift
                ;;
        esac
        # Setup beam-required vars
        EMU="beam"
        PROGNAME="${0#*/}"

        export EMU
        export PROGNAME

        # Store passed arguments since they will be erased by `set`
        ARGS="$@"

        # Build an array of arguments to pass to exec later on
        # Build it here because this command will be used for logging.
        set -- "$BINDIR/erlexec" $FOREGROUNDOPTIONS \
            -boot "$BOOTFILE" -mode "$CODE_LOADING_MODE" \
            -boot_var ERTS_LIB_DIR "$ERTS_LIB_DIR" \
            -config "$RELX_CONFIG_PATH" \
            -args_file "$VMARGS_PATH" \
            -pa ${__code_paths}

        # Dump environment info for logging purposes
        echo "Exec: $@" -- ${1+$ARGS}
        echo "Root: $ROOTDIR"

        # Log the startup
        echo "$RELEASE_ROOT_DIR"
        logger -t "$REL_NAME[$$]" "Starting up"

        # Start the VM
        exec "$@" -- ${1+$ARGS}
        ;;
    rpc)
        # Make sure a node IS running
        if ! relx_nodetool "ping" > /dev/null; then
            echo "Node is not running!"
            exit 1
        fi

        shift

        relx_nodetool rpc $@
        ;;
    rpcterms)
        # Make sure a node IS running
        if ! relx_nodetool "ping" > /dev/null; then
            echo "Node is not running!"
            exit 1
        fi

        shift

        relx_nodetool rpcterms $@
        ;;
    eval)
        # Make sure a node IS running
        if ! relx_nodetool "ping" > /dev/null; then
            echo "Node is not running!"
            exit 1
        fi

        shift
        relx_nodetool "eval" $@
        ;;
    status)
        # Make sure a node IS running
        if ! relx_nodetool "ping" > /dev/null; then
            echo "Node is not running!"
            exit 1
        fi

        [ ! -z "${STATUS_HOOK}" ] && [ "$SCRIPT_DIR/$STATUS_HOOK" ] && . "$SCRIPT_DIR/$STATUS_HOOK" $@
        ;;
    help)
        if [ -z "$2" ]; then
            relx_usage
            exit 1
        fi

        TOPIC="$2"; shift
        relx_usage $TOPIC
        ;;
    *)
        relx_usage
        exit 1
        ;;
esac

exit 0
